22 research outputs found
From cells to circuits:Transdiagnostic mechanisms of dysfunction in pompe disease and niemann-pick disease type c
Get PDFData-driven animation of hand-object interactions
No full textAnimating hand-object interactions is a frequent task in applications such as the production of 3d movies. Unfortunately this task is difficult due to the hand's many degrees of freedom and the constraints on the hand motion imposed by the geometry of the object. However, the causality between the object state and the hand's pose can be exploited in order to simplify the animation process. In this paper, we present a method that takes an animation of an object as input and automatically generates the corresponding hand motion. This approach is based on the simple observation that objects are easier to animate than hands, since they usually have fewer degrees of freedom. The method is data-driven; sequences of hands manipulating an object are captured semi-automatically with a structured-light setup. The training data is then combined with a new animation of the object in order to generate a plausible animation featuring the hand-object interaction. © 2011 IEEE.status: Publishe
Learning probabilistic non-linear latent variable models for tracking complex activities
No full textA common approach for handling the complexity and inherent ambiguities of 3D human pose estimation is to use pose priors learned from training data. Existing approaches however, are either too simplistic (linear), too complex to learn, or can only learn latent spaces from "simple data", i.e., single activities such as walking or running. In this paper, we present an efficient stochastic gradient descent algorithm that is able to learn probabilistic non-linear latent spaces composed of multiple activities. Furthermore, we derive an incremental algorithm for the online setting which can update the latent space without extensive relearning. We demonstrate the effectiveness of our approach on the task of monocular and multi-view tracking and show that our approach outperforms the state-of-the-art.status: Publishe
Mejora iterativa de un sistema de control de trayectorias para un dron.
Get PDFEste trabajo busca mejorar las trayectorias repetitivas de drones en tareas como inspección y vigilancia, corrigiendo errores mediante un algoritmo de aprendizaje automático y datos de un sistema de captura de movimiento. Se realizaron simulaciones en Matlab para optimizar el algoritmo, logrando reducir errores y acelerar la convergencia. Posteriormente, se validaron los resultados en un dron Tello EDU, implementando el control iterativo para mejorar la trayectoria. Finalmente, se optimizaron parámetros del algoritmo mediante simulaciones, logrando una convergencia más rápida a costa de oscilaciones iniciales, con perspectivas de futuras mejoras y aplicaciones.<br /
Case report: Chronic pain in a pediatric patient with late-onset pompe disease
Get PDFPompe disease (PD) is a rare inherited metabolic disorder of deficient or absent acid alpha-glucosidase (GAA), resulting in defective lysosomal glycogen catabolism. Muscle weakness, respiratory deficiency and gastrointestinal symptoms are commonly monitored in PD. However, pain and associated psychological symptoms are less focused upon. A pediatric patient with late-onset Pompe disease (LOPD) comorbid with chronic pain is presented. Symptoms of pain in the feet were first reported between 6 and 7 years of age and were attributed to growing pains. Following progression of lower body pain, weakness, fatigue, and difficulties with ambulation, a thorough clinical assessment including genetic testing was performed, which led to a diagnosis of LOPD at 9 years of age. ERT with recombinant human alglucosidase alfa was subsequently started. The patient’s clinical status is compounded by depressed mood, anxiety, and attention deficit hyperactivity disorder, which may further exacerbate pain. A multidisciplinary pain treatment approach consisting of orthopedics, physical therapy, and psychosocial therapy aimed at enhancing pain coping skills is described for this LOPD patient. This case highlights the need for a greater understanding of pain generation and identification of optimized pain treatment approaches in children with LOPD that can be implemented alongside ERT
Peripheral Pain Captured Centrally:Altered Brain Morphology on MRI in Small Fiber Neuropathy Patients With and Without an SCN9A Gene Variant
Get PDFThe current study aims to characterize brain morphology of pain as reported by small fiber neuropathy (SFN) patients with or without a gain-of-function variant involving the SCN9A gene and compare these with findings in healthy controls without pain. The Neuropathic Pain Scale was used in patients with idiopathic SFN (N = 20) and SCN9A-associated SFN (N = 12) to capture pain phenotype. T1-weighted, structural magnetic resonance imaging (MRI) data were collected in patients and healthy controls (N = 21) to 1) compare cortical thickness and subcortical volumes and 2) quantify the association between severity, quality, and duration of pain with morphological properties. SCN9A-associated SFN patients showed significant (P < .017, Bonferroni corrected) higher cortical thickness in sensorimotor regions, compared to idiopathic SFN patients, while lower cortical thickness was found in more functionally diverse regions (eg, posterior cingulate cortex). SFN patient groups combined demonstrated a significant (Spearman's ρ = .44–.55, P = .005–.049) correlation among itch sensations (Neuropathic Pain Scale-7) and thickness of the left precentral gyrus, and midcingulate cortices. Significant associations were found between thalamic volumes and duration of pain (left: ρ = −.37, P = .043; right: ρ = −.40, P = .025). No associations were found between morphological properties and other pain qualities. In conclusion, in SCN9A-associated SFN, profound morphological alterations anchored within the pain matrix are present. The association between itch sensations of pain and sensorimotor and midcingulate structures provides a novel basis for further examining neurobiological underpinnings of itch in SFN. Perspective: Cortical thickness and subcortical volume alterations in SFN patients were found in pain hubs, more profound in SCN9A-associated neuropathy, and correlated with itch and durations of pain. These findings contribute to our understanding of the pathophysiological pathways underlying chronic neuropathic pain and symptoms of itch in SFN.</p
The experience of living with Niemann–Pick type C: a patient and caregiver perspective
No full textAbstract Background Niemann–Pick disease type C (NPC) is a rare inherited lysosomal storage disease typified by accumulation of cholesterol and other lipids in late endosomes/lysosomes, thereby resulting in a spectrum of neurological, psychiatric, and systemic symptoms (notably liver disease). Though it is well-known that NPC exacts a physical and emotional toll on both patients and caregivers, the burden of NPC can vary between patients, while the challenges of living with NPC can evolve over time (i.e., from time of diagnosis to the present day). To further grasp patient and caregiver perceptions and experiences with NPC, we carried out focus group discussions with pediatric and adult individuals with NPC (N = 19), with partial or full representation of the patient by their caregiver. Furthermore, we utilized our NPC focus group discussion to provide guidance on study design parameters and feasibility of prospective investigations aiming to characterize the central manifestations of NPC using neuroimaging, specifically, magnetic resonance imaging (MRI) methodology. Results Focus group discussions revealed that neurological signs, including declining cognition, memory loss, and psychiatric symptoms, as well as increasingly impaired mobility and motor function, are among the most pressing past and current concerns for patients and caregivers. Moreover, several participants also expressed concern over a loss of independence, social exclusion, and uncertainty for what the future holds. Caregivers described the challenges that participation in research poses, which included logistical difficulties mainly due to traveling with medical equipment and the need for sedation in a minority of patients when undergoing MRI. Conclusions The findings derived from focus group discussions highlight the outstanding challenges that NPC patients and their caregivers face daily, while also providing direction on the potential scope and feasibility of future studies focusing on the central phenotypes of NPC
Pharmacological Interventions Targeting Pain in Fibrous Dysplasia/McCune–Albright Syndrome
No full textFibrous dysplasia (FD) is a rare, non-inherited bone disease occurring following a somatic gain-of-function R201 missense mutation of the guanine-nucleotide binding protein alpha subunit stimulating activity polypeptide 1 (GNAS) gene. The spectrum of the disease ranges from a single FD lesion to a combination with extraskeletal features; an amalgamation with café-au-lait skin hyperpigmentation, precocious puberty, and other endocrinopathies defines McCune–Albright Syndrome (MAS). Pain in FD/MAS represents one of the most prominent aspects of the disease and one of the most challenging to treat—an outcome driven by (i) the heterogeneous nature of FD/MAS, (ii) the variable presentation of pain phenotypes (i.e., craniofacial vs. musculoskeletal pain), (iii) a lack of studies probing pain mechanisms, and (iv) a lack of rigorously validated analgesic strategies in FD/MAS. At present, a range of pharmacotherapies are prescribed to patients with FD/MAS to mitigate skeletal disease activity, as well as pain. We analyze evidence guiding the current use of bisphosphonates, denosumab, and other therapies in FD/MAS, and also discuss the potential underlying pharmacological mechanisms by which pain relief may be achieved. Furthermore, we highlight the range of presentation of pain in individual cases of FD/MAS to further describe the difficulties associated with employing effective pain treatment in FD/MAS. Potential next steps toward identifying and validating effective pain treatments in FD/MAS are discussed, such as employing randomized control trials and probing new pain pathways in this rare bone disease
Diffusion Tensor Imaging Reveals Altered Centrality of Pain-Related Regions in SCN9A-Associated Small Fiber Neuropathy
No full textBackground and Purpose: Small fiber neuropathy (SFN) is a neuropathic disorder that is associated with chronic pain. While most SFN cases are idiopathic, SFN can also have hereditary causes. For example, rare SCN9A gene mutations can impair the Na<inf>V</inf>1.7 sodium channel, which leads to dorsal root ganglion neuron hyperexcitability, causing SFN. Although chronic pain may induce cerebral changes, the specific structural brain alterations in SCN9A-associated SFN (SFN-SCN9A) remain insufficiently characterized. Therefore, potential alterations in the structural brain network of idiopathic SFN and SFN-SCN9A were explored. Methods: Ten SFN-SCN9A patients, 20 idiopathic SFN patients, and 20 controls were included. All participants underwent 3-Tesla diffusion MRI (66 gradient directions, b-value = 1200 s/mm<sup>2</sup>), and the brain network was quantified using nodal importance, which describes the influence of a group of regions on the whole network. Results: The nodal importance of pain-associated regions (postcentral gyrus, insular cortex, anterior cingulate cortex, and thalamus) was increased in SFN-SCN9A patients compared to controls (ß = 0.43, p = 0.02) and idiopathic SFN patients (ß = 0.43, p = 0.02). Moreover, higher self-reported pain was associated with higher nodal importance of pain-associated regions in the SFN-SCN9A group (r = 0.67, p = 0.03), while this effect was not observed in the idiopathic SFN patients (r = -0.22, p = 0.34). As self-reported pain did not differ between the SFN groups, it is likely specific to the SCN9A-mutation and not to differences in pain intensity. Conclusion: Combined, these results suggest the potential involvement of a distinct structural pathway related to pain processing in SFN-SCN9A
